Rotative device for rock drills



Filed April 26, 1923 za f ' 8W aM vea Patented Jan. 12, 1926.

UNITED STATES PATENT OFFICE.

GUSTAVE M..1\TELL, or CLEVELAND, 01110, ASSIGNOR TO THE CLEVELAND ROCK DRILL COMPANY, or CLEVELAND, onro.

ROTATIVE DEVICE FOR ROCK DRILLS.

Application filed April 26, 1923.

' To all whom it may concern:

Be it known that I, GUSTAVE M. NELL, a citizen of the United States, residing at Cleveland, in the county of Guyahoga and State of Ohio, have invented new and useful Improvements in Rotative Devices for Rock Drills, of which the following is a specification.

The present invention. is directed to improvements in rotative devices for rock drills.

The primary object of the invention is to provide a novel form of worm drive for rotating the drill steel through the medium of an independent motor, the construction being such that the worm wheel will be held positively alined for engagement .with the worm shaft to prevent undue friction between the respective threads of the worm wheel and shaft and assure an even drive.

A further object of the invention is to provide means whereby the worm wheel will be held against tilting movement to assure alinement thereof, this being accomplished by providing a flange thereon and arranging the worm wheel so that its outside diameter will engage the inner diameter of the rotating motor supporting sleeve, the construction being such that the worm wheel can freely rotate, but is held posi tively against longitudinal movement.

With these and other objects in view this invention resides in the novel features of construction, formation, combination and arrangement of parts to be hereinafter more fully described, claimed and illustrated in the accompanying drawings, in which The figure represents a longitudinal sectional view through the device.

Referring to the drawing, 1 designates the cylinder, and engaged with the forward end thereof'is a spacer head 2, said head being provided with an annular extension 3. A sleeve 4 is employed and has formed therein a counter-bore 5 and a resultant annular shoulder 6, which is normally held spaced from the outer end of the extension which is engaged in the counter-bore of the sleeve. Rotatably mounted in the sleeve 4: and having its outside diameter bearing against the interior wall thereof is a worm wheel 7, the rear end of which is provided with an annular flange 8 which has its front face engaged with the shoulder 6 and its Serial No. 634,839.

the extension 3. It will be obvious that this flange can freely rotate, but at the same time longitudinal movement thereof is prevented as Well as any tilting action owing to the fact that the faces thereof are engaged, respectively, with the shoulder 6 and forward end of the extension 3. From the foregoing it will be apparent that owing to the presence of the flange 8 the worm wheel will be held in perfect alinement for co-operation with the worm shaft.

The bore 9 of the worm wheel is of greater diameter than the extension 10 of the hammer 11, said hammer reciprocating in the cylinder 1 in the usual manner vhich being the case the hammer extension can freely reciprocate without unnecessary friction when operating to strike the drill. steel 12. c

This steel is engaged in the chuck 13 which is rotatably engaged in the front head 14 which is held in clamped engagement with the forward end of the sleeve 3 by the usual side rods (not shown). The rear end of the chuck extends into the sleeve 4: and has therein notches 15 in which are engaged the lugs 16 carried by the forward end of the worm wheel 7 thereby interlocking the worm wheel and chuck for simultaneous rotation. The upper portion of the sleeve 4 is provided with a casing 17 in which is mounted a motor 18, preferably of the geared piston type and connected with the motor is a worm shaft 19, shown in dotted lines, which meshes with the worm wheel 7 in the usual manner and serves to impart rotary motion to the worm wheel, and thus to the chuck when the motor is operating. It will be of course understood that air under pressure can be admitted to the motor 18 for driving the same in any approved manner. The drill steel 12 is of the lug type and consequently is compelled to rotate with the chuck as is the usual practice.

What is claimed is:

In a rock drill, the combination with a cylinder, of a spacer head connected with the cylinder and provided with an annular extension, a hammer reciprocable in the cylinder, a sleeve connected with the spacer head and having a drill steel rotating motor carried thereby, an annular shoulder formed within the sleeve and spaced from the anrear face engaged with the forward end of nular extension, a worm wheel located in 0? ieee dian'reter than the here (if the Worm wheel and mewnbie therein, a drill steel 10- 10 tilting: chuck interlocked with the Worm Wheel, and a worm shaft co-operative with the Worm wheel and driven by said motor.

In testimony whereof I have hereunto set my hand.

GUSTAVE M. NELL. 

